This invention relates generally to equipment for separating units from a stack and for facilitating lifting and handling of those units. More specifically, this invention relates to a device particularly designed for separating and lifting units, such as relatively fragile insulated glass window or door units or the like, from a stack of units.
In many manufacturing processes, it is necessary or desirable to separate partially manufactured units or items one at a time from a stack thereof and to lift and handle those units preparatory to performance of subsequent manufacturing or assembly operations. Such separating, lifting, and handling of the units, however, can be a particularly delicate procedure when the stacked units are, for example, relatively fragile, bulky, difficult to grasp, or when the units tend to stick to one another.
By way of one specific example, insulated glass window or door units are normally manufactured by forming a stack of identical units each comprising a pair of glass panes or the like spaced from one another by a slightly inset peripheral spacer. After the stack is formed, a curable sealant and adhesive material, such as a thermosetting rubber-based composition, is applied about the periphery of the stacked units to bond the glass panes and spacer of each unit with respect to one another and to seal the volume between the glass panes against ingress of air or moisture. However, the sealant-adhesive material typically overlaps slightly the margins of adjacent units in the stack such that the units are normally stuck to one another when the sealant-adhesive material cures. As a result, it is particularly difficult to separate the units from one another for subsequent manufacturing steps, such as installation thereof into appropriate frames.
Typically, separation of the stacked units is accomplished by manually cutting the sealant-adhesive material with a razor knife or the like to free the units from each other and thereby permit them to be lifted manually from the stack. However, this cutting procedure is relatively time-consuming and hazardous to the worker and all too frequently results in errant cuts destroying the peripheral seal provided by the sealant-adhesive material. Such damage to the peripheral seal is extremely difficult to detect visually, but nevertheless constitutes a major cause of warranty claims by consumers since it permits moisture to enter the volume between the two panes of a window or door unit whereby the unit will fog up during use. Moreover, even if the sealant-adhesive material is cut properly, the fragile units are particularly cumbersome to grasp and carry to a subsequent manufacturing station.
The present invention overcomes these problems and disadvantages by providing a device for quickly and easily separating relatively fragile units, such as insulated glass window or door units, from a stack of units one at a time without damage to the units, wherein the device further facilitates handling and carrying of the units to an alternative location.